Add explicit align-padding for:
* the request "SetPictureFilter":
  Added 4-byte align-pad between list "filter" and list "values"
  The spec does not show the padding:
    http://cgit.freedesktop.org/xorg/proto/renderproto/tree/renderproto.txt?id=renderproto-0.11.1#n721
  But there has to be padding to make accesses to 32-bit values in list
  "values" aligned.
  The Xlib implementation at
    http://cgit.freedesktop.org/xorg/lib/libXrender/tree/src/Filter.c?id=libXrender-0.9.9#n160
  correctly does the padding:
  The string "filter" is written with "Data" which does 4-byte padding at the end:
    http://cgit.freedesktop.org/xorg/lib/libX11/tree/include/X11/Xlibint.h?id=libX11-1.6.3#n535
    http://cgit.freedesktop.org/xorg/lib/libX11/tree/src/xcb_io.c?id=libX11-1.6.3#n484



Signed-off-by: Christian Linhart <chris@demorecorder.com>
Reviewed-by: Peter Harris <pharris@opentext.com>